From 95a16160ca1d75c66bf7a1c5e0bcaffb18e7c7fc Mon Sep 17 00:00:00 2001 From: Arunpravin Paneer Selvam Date: Wed, 16 Jul 2025 13:21:24 +0530 Subject: drm/amdgpu: Reset the clear flag in buddy during resume MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit - Added a handler in DRM buddy manager to reset the cleared flag for the blocks in the freelist. - This is necessary because, upon resuming, the VRAM becomes cluttered with BIOS data, yet the VRAM backend manager believes that everything has been cleared. v2: - Add lock before accessing drm_buddy_clear_reset_blocks()(Matthew Auld) - Force merge the two dirty blocks.(Matthew Auld) - Add a new unit test case for this issue.(Matthew Auld) - Having this function being able to flip the state either way would be good. (Matthew Brost) v3(Matthew Auld): - Do merge step first to avoid the use of extra reset flag. Signed-off-by: Arunpravin Paneer Selvam Suggested-by: Christian König Acked-by: Christian König Reviewed-by: Matthew Auld Cc: stable@vger.kernel.org Fixes: a68c7eaa7a8f ("drm/amdgpu: Enable clear page functionality") Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3812 Signed-off-by: Christian König Link: https://lore.kernel.org/r/20250716075125.240637-2-Arunpravin.PaneerSelvam@amd.com --- drivers/gpu/drm/drm_buddy.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) (limited to 'drivers/gpu/drm/drm_buddy.c') diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c index 241c855f891f..66aff35f8647 100644 --- a/drivers/gpu/drm/drm_buddy.c +++ b/drivers/gpu/drm/drm_buddy.c @@ -404,6 +404,49 @@ drm_get_buddy(struct drm_buddy_block *block) } EXPORT_SYMBOL(drm_get_buddy); +/** + * drm_buddy_reset_clear - reset blocks clear state + * + * @mm: DRM buddy manager + * @is_clear: blocks clear state + * + * Reset the clear state based on @is_clear value for each block + * in the freelist. + */ +void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear) +{ + u64 root_size, size, start; + unsigned int order; + int i; + + size = mm->size; + for (i = 0; i < mm->n_roots; ++i) { + order = ilog2(size) - ilog2(mm->chunk_size); + start = drm_buddy_block_offset(mm->roots[i]); + __force_merge(mm, start, start + size, order); + + root_size = mm->chunk_size << order; + size -= root_size; + } + + for (i = 0; i <= mm->max_order; ++i) { + struct drm_buddy_block *block; + + list_for_each_entry_reverse(block, &mm->free_list[i], link) { + if (is_clear != drm_buddy_block_is_clear(block)) { + if (is_clear) { + mark_cleared(block); + mm->clear_avail += drm_buddy_block_size(mm, block); + } else { + clear_reset(block); + mm->clear_avail -= drm_buddy_block_size(mm, block); + } + } + } + } +} +EXPORT_SYMBOL(drm_buddy_reset_clear); + /** * drm_buddy_free_block - free a block * -- cgit v1.2.3